1. Field of the Invention
This invention relates to a filter press type ion exchange membrane-method electrolysis cell used, for example, in the electrolysis of alkali metal halides.
2. Description of the Prior Art
In a conventional filter press type ion exchange membrane-method electrolysis cell, the piping system is complicated because the pipe for withdrawing electrolytic solution and gas generated during electrolysis is secured to each electrolysis compartment from the outside through an electrode frame in each electrode structure. This causes a great deal of difficulty in installing or repairing the electrolysis cell.
In an attempt to overcome this difficulty, U.S. Pat. No. 4,069,129 suggests a filter press type electrolysis cell in which a top portion and a bottom portion of an electrode frame are constructed as hollow bodies so that the bottom hollow portion is used as a pipe for introduction of electrolytic solution and the electrolytic solution and gas generated during electrolysis are discharged from the top hollow portion.
In the electrolysis cell disclosed in U.S. Pat. No. 4,069,129, an outlet for gas generated during electrolysis and electrolytic solution is located in the top hollow portion of the electrode frame, and therefore, it is necessary to provide at the side portion of the electrolysis cell a piping system for withdrawing the gas generated during electrolysis and the electrolytic solution. Thus, the problem of piping is not improved very much as compared with the conventional electrolysis cell.
U.S. Pat. No. 4,069,129 further discloses that it is desirable to use a hollow structure as the side portion of the electrode frame, and use the hollow side portion for circulation of electrolytic solution (see column 3, lines 3 et seq. of U.S. Pat. No. 4,069,129). Circulation of electrolytic solution at both side portions, however, is not sufficient, and uniform circulation of the entire electrolytic solution is not obtained.